Cloth shoe construction



66 D. c. JOHNSON 3,264,761

CLOTH SHOE CONSTRUCTION Filed Sept. 24, 1965 I INVENTOR. DONALD C. JOHNSON Ohio Filed Sept. 24, 1965, Ser. No. 489,880 1 Claim. (Cl. 36-3) The invention relates to a novel construction for cloth shoes which provides improved comfort, durability and appearance.

Cloth shoes, also called canvas shoes or tennis shoes, have become increasingly popular in recent years for general wear and are now being manufactured in large quantities, particularly for childrens wear. Cloth shoes can be manufactured inexpensively by modern methods, and they are convenient to use because they can be laundered in an automatic washing machine.

In a relatively small number of cloth shoes, the uppers are made of a single layer of heavy woven fabric, but a heavy woven fabric is too expensive for ordinary use in constructing the uppers of cloth shoes.

The material ordinarily used for making the uppers of cloth shoes is a two-ply material in which the outer ply consists of a relatively durable, decorative fabric which is either white, or printed in a pattern, or dyed in a solid color. The types of fabric which are commonly used for the outer ply of this material include bleached or dyed duck or drill and printed cotton sheeting. The inner ply usually consists of cheap, unbleached cotton sheeting or drill which is glued or cemented to the outer ply.

It has been necessary heretofore to use such a twoply material for the uppers of cloth shoes in order that the shoes may be made at a reasonably low cost. A relatively cheap material is used for the inner ply, and a fabric of relatively light weight is used for the outer ply. The stiffening action of the inner ply makes it possible to use for the outer ply a fabric of much lighter weight than could be employed if the inner ply were omitted.

This two-ply material, which is being used in large quantities in manufacturing the uppers of cloth shoes, has certain definite disadvantages. One disadvantage is that the adhesive used to cement the two plies together has the effect of sealing the pores of the fabric so that the two-ply material is impervious to the passage of air or moisture. -The impervious nature of the two-ply material is a disadvantage when the material is used to make the uppers of cloth shoes, because the material cannot breathe" and the shoes therefore are uncomfortable in hot weather, causing the feet to perspire and to become irritated, and promoting the growth of fungus.

Another disadvantage of this two-ply material is that it is incapable of stretching. As the result of the inability of this material to stretch, cloth shoes having uppers made of this material tend to be ill-fitting.

The principal object of the invention is to provide a novel construction for cloth shoes which permits the shoes to be made at reasonable cost, and which includes improved uppers which are permeable and capable of breathing, and also are capable of stretching sufficiently to conform to the foot, which are smooth and soft on the inside so that the shoes are comfortable to wear even without socks, and which present a smooth, wrinkle-free and durable exterior. More specific objects and advantages are apparent from the following description, in which reference is had to the accompanying drawings.

FIG. 1 of the drawings is a perspective view of a cloth shoe.

FIG. 2 is a diagrammatic view of an apparatus for producing the material used for the uppers of shoes embodying the invention.

United States Patent 3,264,761 Patented August 9, 1966 FIG. 3 is a section of the material, taken on the line 33 of FIG. 2.

These specific drawings and the specific description that follows are intended to disclose and illustrate and not to limit the invention.

A cloth shoe embodying the present invention has an upper made of a sandwich material consisting of an inner layer of knitted textile fabric, an outer layer of textile fabric, and a layer of open-cell latex foam cast between said inner and outer fabric layers, the interstices in the fabric layers being open so that the sandwich material is permeable.

It has been discovered that the layer of open-cell latex foam which is cast between the inner and outer fabric layers in the material used for the uppers of shoes embodying the present invention has a peculiar supporting action on the fabric layers which substantially increases the wearability of both of the fabric layers. Thus it is possible to use a relatively light-weight knitted cloth for the inner layer, and to use a relatively light-weight decorative woven cloth for the outer layer.

The intermediate layer of foam also reenforces the inner and outer fabric layers to the proper extent so that the uppers of shoes embodying the present invention do not stretch out of shape, but stretch sufficiently to conform to the feet so that the shoes are well-fitting.

The novel construction of the present invention provides uppers which have excellent body, so that the uppers of the shoes are well rounded and free from wrinkles and are not flabby, and the shoes present an excellent appearance.

The use of knitted fabric for the inner layer in the uppers of shoes embodying the present invention is made possible by the supporting action of the intermediate layer of latex foam. Because of the use of knitted fabric for the inner layer of the uppers, and because of the gentle supporting action of the intermediate layer of latex foam, the present shoes feel very smooth and soft on the feet and are exceptionally comfortable, even when worn on bare feet.

The use of knitted fabric for the inner layer in the uppers of shoes embodying the invention is important for another reason. Because of the presence of the intermediate layer of latex foam, the three-ply material used to produce the uppers of the present shoes is relatively thick, so that bending of the material produces a rela tively great compressive stress on the concave side of the bend. It has been discovered that it is necessary to use knitted fabric for the inner layer in order to prevent'the inner layer from wrinkling. It has been found that knitted fabric absorbs the compression without forming wrinkles, which would spoil the appearance of the shoes.

The inner layer of the sandwich material used for making the uppers of shoes embodying the invention consists of a knitted textile fabric such as jersey or tricot. The knitted fabric may be cotton, nylon, acetate, viscose, Dacron, or any desired combination of those materials. The knitted fabric may be very light in weight, so that the knitted fabric itself has very little body. However, the combination of the two layers of fabric with the layer of open-cell latex foam cast between the two layers has excellent body. The function of the layer of knitted fabric is to protect the latex foam layer against abrasion and to form a smooth surface so that the shoe slides on easily. The inner layer of knitted fabric also forms a soft surface which is compressible so that it does not wrinkle.

The outer layer of the sandwich material used for making the uppers of shoes embodying the invention conthe invention may ibelight iuweight because thecome binationof thetwo layers of fabric with the intermediate layer of latex foamp-rov ides .a multi-ply materialofexcellent body. I

. One important aspect of the present invention is that the outer layer does not need to consist of knitted fabric andmay consist of ordinary woven fabric because .the outer. layer in the; shoe uppers is on the convex side :at every point and thereforeis not subject to wrinkling; The outer layer in the practice of the invention may consist of any durable, decorative textile fabric such as bleached or dyed duck or drill, cotton sheeting (usually printed with a pattern), dyed denim, or dyed .or printed corduroy. Thus the material used for the outer layer maybe either white, or dye-d with a solid color, or printed with a decorative pattern.

Another important feature ofthe present invention 1s thatthe intermediate layer is an open-celllatex foam 7 which is cast between the inner and outer fabric layers,

the interstices in the fabric layers being openso that the sandwich is permeable.

The fact that the latex foam is cast between the inner and outer fabric layers isv important, because this type of construction leaves the fabric layers unimpregnated and leaves the interstices in the fabric layers open. Although it is possible to cast a latex foam between the fabric layers,- other types of foam. cannot be produced ingthis manner. 'It is not 'feasible touse a foam layer which is produced separately in the form of a sheet, because the operation of adhering the independently produced foam layer to the fabric layers would destroy the permeability of the fabric layers. Such destruction of the permeability; of the fabric layers would occur whether the independently produced foam layer were cemented to the fabriclayers or were fused to the fabric layers. If a cement were used tosecure an independently'produced foamslayer to' the fabric layers, the cement would impregnate the fabric layers so ,as to render them impermeable. fusing an independently produced foam layer to the fabric layers would seal the interstices in thefabric layers with the fused material.

. It is only by the casting of a layer of open-cell foam Y between theinner and outer fabric layers that the inter.:

stices in the fabric layers are left open so as to produce a sandwich material which is breathing when used to form the shoe uppers.

In the practice of the present invention it'is desirable to use a latex foam which is water-resistant, so thatthe shoes constructed in accordance with the invention canbe laundered in an automatic washing machine.

The layer of open-cell latex foam which is cast between persion in a continuous aqueous phase, and the emulsion is highly fluid so that it can be foamed. The usual method of transforming the wet foam'into a solid foam consists in'causing gelling to take place so as to convert the polymer from a dispersed phase into a continuous phase. In'

this phase inversion, the aqueous phase becomes the dis persed phase.

In order to cause .gelation of the polymer-to occur after the wet foam has been produced, a substance such as a soap which has been acting as an emulsion stabilizer to hold the polymer in a dispersed phase may be destroyed or inactivated, for example by reaction with'an acidic material which .is added. An example of an acidic material which is commonly usedas a gelling agentin Similarly,

permeable and capable of" produoedby the known methodsof casting.

4. the production ofa solid latex foam is sodium silico:v fluoride? The aqueous emulsion or latex may be converted into a wet, foam by pumping it underpressure through a conventionalfoamer hea-d,..in which {it may .be'mixed with compressed ai-r, orby the use :of whipping apparatus.

During :the foaming step, the volume of emulsion is increased to 5-l5 times its initial volume. A gelling agent, such-as a concentrated -aqueous solution :of sodium. silicofi-uoride, maybe introduced intothe latex just before it is foamed; The amount of gelling agent used and the temperature of the latex should be such that-gelling takes place, to convert the wet foam to argelled foam, after the foam layer is in place betweentthe two fabric layers.

The gelling of the foamis followed by drying andcurmg.

In the operation ofthe apparatus shown in FIG. 2, a continuously moving stainless steel belt 10 is carried on r0lls1 11,-..one of whichis driven at the desired speed; Another rolllzi is mounted slightly above one of the rolls 11. and is -driven;at the same peripheral speedas the underlying roll '11.

A continuous strip of woven fabric 13which is to form the outer layer, is fed from a suitable source such as: a supp-ly roll and is carried onathe surface of the stainless steelbelt 110's A continuousstrip:of=knitted.fabric.14 I to form the inner layer is fed from a suitable supply roll upper roll and iscarried around thelower'surface of the 12.: A rear wall 15 forretaining a supply of wet foam 16 extends woven fabric 13 to enter.

' ously supplied :from a foamer. head or other suitable the temperature in the-oven thema-terial may be'passed through the oven during a period of ten to fifteenrninutes. This heat treatment under a doctor source, and. is carried on to a layer :of the desired thickness. The strip of knitted fabric '14 isapplied on 'top of this layer. 1

The sandwich consisting of the two layers of fabric and the intermediate layer of wet foam is carried on the stainless steel, belt 10 into a suitable drying oven 18, and the finishedproduct leavesthe stainless steel belt as thebelt passes over the remote roller. 1=1.t. i

The oven I18 preferably' is a circulating-air oven. If is between 280 and.400 F 7 causes drying of'the foam and curing of the polymer, for

exampleby sulfur vulcanizationor by cross-linking. Conthe foam occurs during the drying operation, so that an open'cell or permeable siderable breakage of the cells in foam is produced. 5.

It has been found that the .wet. foam -16,*which may consist of about'80 or appreciably impregnate. thethe fabric remain'spenmeable'. 1

The thickness of thefinished sandwichmaterial, shown in FIG. 3, may be between and 3/8 inch, for example inch. i

The sandwich material' may .be-used in conventional shoe-making machinery to form the uppers of shoes such' as that shown in FIG. 1.1

Thepreferred type of polymeremulsion or latex for use in making the intermediate foam layer is an emulsion of a copolymer of at least two ethylenically unsat-.

urated monomers, one of which is styrene or a monomer that .is. copolymerizable with styrene, and another of which has ;a pendant hydrophilic substituent group' s-uchas a carboxy group; The advantage of employing an emulsion of this type of :copolymer is that a foam of superior washability may be produced by using, to assist in the gelling of the foam, across-linking agent, such as melamine or a formaldehyde condensate of melamineythat is reactive with the pend-ant. hydrophilic sub-' s'tituent group. Anexample of this type of latex is an close to the upper surface of one of the rolls- 1/1, with just'sufiicient clearance to permit the stripof Thewet foam 16 :is continu-:'

the strip of woven fabric .13 blade 17,whi'ch levels the wet foam 16:"

of air by volume, does not fabric layers 13 and 114, so that the intersticesin the fabric layers. remain open and aqueous emulsion containing about 70 weight percent of a terpolymer consisting of about 5 weight percent of acrylic acid, about 35 weight percent of styrene and 60 weight percent of 1,3-butadiene. This latex (100 dry parts) may be stirred with 80 parts of aluminum hydrate powder, 1 part of alkylated phenol anti-oxidant, 3 parts of a petroleum wax emulsion, 1 part of sodium coco sulfate and .25 dry part of 4000 cps. methyl cellulose.

Before foaming, a Water soluble melamine-formaldehyde reaction product (5 dry par-ts) may be added and the pH of the emulsion adjusted to 10.5 by addition of ammonium hydroxide. The resulting final product has excellent compression set resistance, washability and aging properties.

Other types of polymer emulsions which are in general use for the production of solid foams include natural rubber latex, certain polymers of 2-chloro-l,3-butadiene, and the GRS cold rubbers.

The polymer emulsions used in the practice of the present invention may be prepared by polymerization in aqueous emulsions containing surfactants, catalysts and other modifiers, and under conditions such as time, temperature, pressure and agitation in accordance with well known principles of emulsion polymerization.

The polymer emulsion that is foamed in the practice of the present invention may contain any of the conventional agent that are required to eifect the final cure of the polymer in the emulsion, such as accelerators and vulcanizing agents, together with other usual ingredients such as anti-oxidants and fillers.

Another example of a latex which is conventionally used for the production of a latex foam is Pliolite 5352 Latex, which is a cold-polymerized latex containing butadiene and styrene in a weight ratio of 70:30 that has been concentrated to a non-volatile content of 69%. A sandwich in which the intermediate foam layer has a density of about 7.5 pound per cubic foot, for use in the practice of the invention, may be produced by the procedure hereinbefore described in which the ingredients of the mixture that is foamed are as follows:

Alkylated phenol anti-oxidant 1 6 Ground felspar filler 68% sulfur dispersion 1.5 Potassium soap of tall oil fatty acids, containing 12% of rosin fatty acids Sodium silicofluoride 2 Diphenyl guanidine .7

The potassium soap used as a foaming agent in this mixture may be replaced by sodium coco sulfate (a mixture of sodium alkyl sulfates in which the alkyl radicals are those corresponding to the carbon chains of the mixture of fatty acids in coconut oil), and the Pliolite 5352 Latex may be replaced by one of the following:

(A) A butadiene-styrene copolymer latex of the GRS 2105 type, containing 62.5 percent solids (Pliolite 2105).

(B) A butadiene-vinyltoluene copolymer latex of the GRS 2000 type (Dow Latex 2582).

(C) A natural rubber latex concentrate containing 62.5 percent solids.

(D) A polychloroprene latex (Neoprene 635).

The present invention is applicable not only to cloth shoes but also to other articles of footwear, such as slippers and boots, having cloth uppers.

Having described the invention, I claim:

An article of footwear comprising a sole and an upper, said upper consisting essentially of a bonded sandwich of an inner layer of knitted textile fabric, an outer layer of textile fabric, and an intermediate layer of open cell cast latex foam which joins the fabric layers directly without the intervention of a bonding layer, the interstices of the fabric layers being open and communicating with the open cell latex foam to permit air to pass through all the layers of the sandwich so that the sandwich is permeable and capable of breathing.

References Cited by the Examiner UNITED STATES PATENTS 2,792,320 5/1957 Bower 16189 3,016,631 l/l962 Servin 369 X 3,052,046 9/1962 Kramer 369 3,130,505 4/ 1964 Markevitch 3645 3,173,826 5/1965 Campbell et .al. l6l-l6l JORDAN FRANKLIN, Primary Examiner.

PATRICK D. LAWSON, Examiner. 

